Breaking bore: Physical observations of roller characteristics |
| |
| Institution: | 1. School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK;2. Spencer Institute of Theoretical and Computational Mechanics, University of Nottingham, Nottingham NG7 2RD, UK;1. School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China;2. Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha, Hunan 410114, China;3. International Research Center of Water Science and Environmental Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China;1. Universidad Tecnológica Nacional, Facultad Regional Córdoba UNT/FRC – CONICET, Maestro M. López esq. Cruz Roja, Argentina, X5016ZAA Córdoba, Argentina;2. Laboratório Nacional de Computação, Científica LNCC/MCTI, Coordenação de Matemática, Aplicada e Computacional, Av. Getúlio Vargas 333, 25651-075 Petrópolis, RJ, Brazil;1. State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China;2. Faculty of Engineering & Informatics, University of Bradford, BD7 1DP, UK |
| |
| Abstract: | In an estuary, a tidal bore is a hydraulic jump in translation generated at the leading edge of the flood tide during the early flood tide under spring macrotidal conditions in a narrow funnelled channel. After formation, the bore is traditionally analysed as a hydraulic jump in translation and its leading edge is characterised by a breaking roller for Fr1 > 1.3–1.5. Herein new unsteady experiments were conducted to investigate in details the upstream propagation of breaking bore roller. The toe perimeter shape fluctuated rapidly with transverse distance and time. A characteristic transverse wave length of the toe perimeter was observed. Both the standard deviation of toe perimeter location and characteristic transverse wave length were comparable to field observations. The celerity of the roller toe fluctuated rapidly with time and space. The instantaneous longitudinal profile of the roller free-surface showed significant temporal and spatial fluctuations. Although the bore propagation may be analysed in an integral form in first approximation, the rapid fluctuations in roller toe perimeter and free-surface profiles indicated a strongly three-dimensional turbulent flow motion. |
| |
| Keywords: | Bore roller Compression waves Open channels Free-surface profile Roller shape Roller toe perimeter Bore celerity Hydraulic jump |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
